Placeholder is displayed instead of actual video track sometimes

[vasilii-kovalev]

It is not specific for this workshop, it occurred in previous ones as well.
In some cases when video starts, a placeholder is displayed instead of actual video track, though I can hear the audio one.

Only page refresh helps.

It happens rarely, but when it does, I can see such errors in console:

[kentcdodds]

cc @dealingwith 👆

[kentcdodds]

Reported 👍 thanks!